Organic/inorganic hybrid solid IHM-2-N3 provided with an azide function, and method for manufacturing same

ABSTRACT

The invention describes a crystallized hybrid solid with an organic-inorganic matrix, of a three-dimensional structure, containing an inorganic network of indium-based metal centers that are connected to one another by organic ligands that consist of the entity —O 2 C—C 6 H 3 —N 3 —CO 2 —. Said solid is called IHM-2-N 3  and has an X-ray diffraction diagram as given below.

TECHNICAL FIELD OF THE INVENTION

This invention relates to a new crystallized hybrid solid with anorganic-inorganic matrix, of a three-dimensional structure, and to theprocess for its preparation starting from the crystallized hybrid solidwith an IHM-2 organic-inorganic matrix. Said new solid, object of thisinvention, carries an azide group and is called IHM-2-N₃ in thedescription below. Said IHM-2-N₃ solid has a crystalline structure thatis identical to the one of the IHM-2 solid from which it is obtained bya post-synthesis functionalization method. Said IHM-2-N₃ solid isadvantageously used in applications as a catalyst or adsorbent or elseas an intermediate compound for obtaining functionalized crystallizedhybrid solids with an organic-inorganic matrix.

STATE OF THE ART

The modification of materials by functionalization is a stage that isoften necessary for the development of solids that have suitableproperties for a given application. Actually, it may be desirable toimprove the physico-chemical properties of a material, by modifying itssurface, for example, so that the new properties that are obtained aftermodifications are more suitable for separation or catalysisapplications.

One of the means that is commonly used to modify the surface of amaterial consists in reacting the functional groups that are initiallypresent on its surface by entities that have the desired groups for theapplication being considered. The groups that are present on the surfaceof a material can be hydroxyl groups (—OH) or any other group (amino-NH₂or —NH—, for example) that it is desired to modify so as to orient thechemical reactivity of the surface of the material. The reagents thatare used will have the necessary functionalities for reacting with thegroups that are initially present on the surface of the material, andthe result of the reaction will be a new chemical group that has thedesired reactivity. One example of such a transformation consists inreacting the hydroxyl groups of the surface of a silica by a silane thatcarries an amine group (D. Brunel, Microporous and Mesoporous Materials,1999, 27, 329-344). Thus, the hydroxyl group is transformed into anamine group that is better able to catalyze basic reactions or tocollect CO₂, for example. This methodology can be applied to anymaterial that initially has reactive groups. These materials can beoxides, zeolites or else organic/inorganic hybrid materials, also calledcoordination polymers.

These coordination polymers, of which the first were described in the1960's, are the object of a growing number of publications. Actually,the effervescence around these materials made it possible to attain anadvanced structural diversity in little time (Férey, G., l'actualitéchimique [Chemical Issues], January 2007, No. 304). Conceptually, theporous hybrid solids with an organic-inorganic mixed matrix are quitesimilar to porous solids with an inorganic skeleton. Like the latter,they combine chemical entities by giving rise to a porosity. The primarydifference resides in the nature of these entities. This difference isparticularly advantageous and is at the origin of the entire versatilityof this category of hybrid solids. Actually, the size of the poresbecomes, by using organic ligands, adjustable by means of the length ofthe carbon-containing chain of said organic ligands. The framework,which in the case of inorganic porous materials, can accept only someelements (Si, Al, Ge, Ga, and optionally Zn) can, in this case, collectall of the cations except for the alkalines. For the preparation ofthese hybrid materials, no specific structuring agent is required; thesolvent provides this effect by itself.

It therefore clearly appears that this family of hybrid materials makespossible a multiplicity of structures and consequently comprises solidsthat are finely adapted to the applications for which they are designed.

The coordination polymers comprise at least two elements that are calledconnectors and ligands whose orientation and number of connecting sitesare decisive in the structure of the hybrid material. From the diversityof these ligands and connectors, an immense variety of hybrid materialsis born, as has already been specified.

Ligand is defined as the organic part of the hybrid material. Theseligands are most often di- or tricarboxylates or derivatives ofpyridine. Some commonly encountered organic ligands are shown below:bdc=benzene-1,4-dicarboxylate, btc=benzene-1,3,5-tricarboxylate,ndc=naphthalene-2,6-dicarboxylate, bpy=4,4′-bipyridine,hfipbb=4,4′-(hexafluoroisopropylidene)-bisbenzoate,cyclam=1,4,8,11-tetraazacyclotetradecane.

Connector is defined as the inorganic entity of the hybrid material. Itmay be a cation by itself, a dimer, trimer or tetramer, or else a chainor a plane.

Within the framework of this invention, the ligand that is used for thepreparation of the solid according to the invention is2-amino-terephthalic acid (NH₂—H₂-bdc). For its part, the inorganicentity that plays the role of connector is indium.

The teams of Yaghi and Férey have thus described a large number of newhybrid materials (series of MOF—“Metal Organic Framework”—and series ofMIL—“Materiaux de l'Institut Lavoisier [Lavoisier InstituteMaterials]”—respectively). Numerous other teams have followed this path,and today, the number of new hybrid materials described is expandingrapidly. Most often, the purpose of the studies is to develop orderedstructures, having extremely large pore volumes, good thermal stability,and adjustable chemical functionalities.

For example, Yaghi et al. describe a series of boron-based structures inthe patent application US 2006/0154807 and indicate their advantage inthe field of gas storage. The patent U.S. Pat. No. 7,202,385 discloses aparticularly complete summary of the structures that are described inthe literature and perfectly illustrates the multitude of materialsalready existing today.

The preparation of organic-inorganic hybrid materials that exhibit areactive organic group (grafted MOF) can be implemented by two primarypaths: functionalization by self-assembly and functionalization bypost-modification. The functionalization by self-assembly is implementedby bringing an organic ligand that has the desired reactive group(graft) into the presence of an inorganic compound that has the role ofconnector. This functionalization method is often difficult to implementbecause of problems linked to the solubilization and the reactivity ofthe functionalized ligands.

In particular, the ligands that carry an —OH, —COOH or —NH₂ group runthe risk of interacting with the inorganic compound (connector) thatthen leads to non-isostructural solids with non-grafted reference MOF.The functionalization by post-modification is an advantageousalternative method that does not exhibit functionalization limits byself-assembly. The functionalization by post-modification consists indirectly modifying the organic group of at least one type of ligand thatis present in the MOF by a chemical reaction (grafting), morespecifically in replacing the initial organic group by an organic groupwhose reactivity is preferred for a subsequent application. This methodsuggests the presence on the initial MOF of an organic group that isaccessible and reactive for grafting. In the literature, theorganic-inorganic hybrid materials that carry a ligand with an —NH₂amino group such as DMOF-1-NH₂ (Z. Q. Wang; K. K. Tanabe, S. M. Cohen,Inorganic Chemistry, 2009, 48, 296-306) are described as good substratesfor the grafting of numerous groups, in particular aldehydes,isocyanates, and acid anhydrides.

DESCRIPTION OF THE INVENTION

This invention has as its object a new crystallized hybrid solid with anorganic-inorganic matrix that has a three-dimensional structure. Thisnew solid is called IHM-2-N₃. It contains an inorganic network ofindium-based metal centers that are connected to one another by organicligands that consist of the entity —O₂C—C₆H₃—N₃—CO₂—(N₃-bdc ligand).

The IHM-2-N₃ crystallized hybrid solid according to the invention has anX-ray diffraction diagram that includes at least the lines that arerecorded in Table 1. This diffraction diagram is obtained byradiocrystallographic analysis by means of a diffractometer by using theconventional method of powders with the Kα1 radiation of copper(λ=1.5406 Å). Starting from the position of diffraction peaks shown bythe angle 2θ, the reticular equidistances d_(hk1) that arecharacteristic of the sample are calculated by applying Bragg'sequation. The measuring error Δ(d_(hk1)) to d_(hk1) is calculated usingBragg's equation based on the absolute error Δ(2θ) that is assigned tothe measurement of 2θ. An absolute error of Δ(2θ) that is equal to±0.02° is commonly allowed. The relative intensity I/I_(o) assigned toeach value of d_(hk1) is measured according to the height of thecorresponding diffraction peak. The X-ray diffraction diagram of theIHM-2-N₃ crystallized hybrid solid according to the invention comprisesat least the lines with given values of d_(hk1) in Table 1. In thecolumn of d_(hk1), the mean values for the inter-recticular distancesare indicated in angstroms (Å). Each of these values is to be assignedthe measuring error Δ(d_(hk1)) of between ±0.3 Å and ±0.01 Å.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an x-ray diffraction diagram of a solid according to theinvention.

TABLE 1 Mean Values for d_(hkl) and Relative Intensities Measured on anX-Ray Diffraction Diagram of the IHM-2-N₃ Crystallized Hybrid Solid. 2Theta (°) d_(hkl) (Å) I/I_(o) 4.68 18.87 mf 8.12 10.88 ff 8.95 9.87 ff9.37 9.43 FF 11.78 7.51 ff 11.94 7.41 f 12.43 7.11 ff 14.08 6.28 ff14.74 6.00 ff 16.34 5.42 f 16.95 5.23 ff 17.45 5.08 ff 18.01 4.92 ff18.80 4.72 mf 18.96 4.68 f 21.03 4.22 ff 23.53 3.78 ff 23.82 3.73 ff25.04 3.55 ff 26.45 3.37 ff 26.68 3.34 ff 27.41 3.25 ff 28.33 3.15 ff28.61 3.12 ff 29.74 3.00 ff 31.24 2.86 ff 32.35 2.77 ff 34.20 2.62 ff35.47 2.53 ff 38.06 2.36 ff 41.71 2.16 ff 42.02 2.15 ff 42.74 2.11 ff43.04 2.10 ff 45.92 1.97 ff 54.57 1.68 ff where FF = Very High; F =High; m = Medium; mf = Medium Low; f = Low; and ff = Very Low. Therelative intensity I/I_(o) is provided in relation to a relativeintensity scale where a value of 100 is assigned to the most intenseline of the X-ray diffraction diagram: ff < 15; 15 ≦ f < 30; 30 ≦ mf <50; 50 ≦ m < 65; 65 ≦ F < 85; and FF ≧ 85.

The IHM-2-N₃ crystallized hybrid solid according to the invention has acrystalline structure with a base or topology that is characterized byits X-diffraction diagram provided by FIG. 1. The crystalline structureof the IHM-2-N₃ crystallized hybrid solid according to the invention isidentical to the one that is exhibited by the IHM-2 crystallized hybridsolid (described below in this description) and from which said IHM-2-N₃solid is obtained, in accordance with the process for preparationdescribed farther down in this description. The IHM-2 crystallizedhybrid solid thus has a chemical composition that has as its basepattern In(OH)(—O₂C—C₆H₃—NH₂—CO₂—). This pattern is repeated n times,with the value of n based on the crystallinity of said solid.

The IHM-2-N₃ crystallized hybrid solid according to the invention has athree-dimensional structure in which the inorganic network—formed byIn³⁺-cation-based metal centers that perform the role of connectors—islinked together by deprotonated terephthalic ligands (—O₂C—C₆H₃—N₃—CO₂—)that carry an N₃ azide group on the aromatic cycle. An essentialcharacteristic of the IHM-2-N₃ crystallized hybrid solid according tothe invention resides in the presence of the azide group on the aromaticcycle of each of the deprotonated terephthalic ligands, morespecifically called 2-azido-terephthalate ligands (denoted N₃-bdc). Thestructure that is obtained, identical to that of the IHM-2 solid, isthree-dimensional. One-dimensional inorganic chains with an —In—O(H)—pattern are linked to one another by deprotonated terephthalic ligands(—O₂C—C₆H₃—N₃—CO₂—). Each indium atom is hexa-coordinated: each indiumatom is surrounded by two oxygen atoms of the hydroxyl groups that arelocated in apical position and by four oxygen atoms that are obtainedfrom four deprotonated terephthalic ligands (N₃-bdc ligand) that arelocated in equatorial position. In addition, each —O₂C—C₆H₃—N₃—CO₂—organic ligand is connected to two indium atoms.

The IHM-2-N₃ crystallized hybrid solid according to the invention thushas a chemical composition that has In(OH)(—O₂C—C₆H₃—N₃—CO₂—) for itsbase pattern. This pattern is repeated n times, with the value of nbased on the crystallinity of said solid.

The IHM-2-N₃ crystallized hybrid solid according to the invention hasalso been characterized by Fourier Transform Infrared (FT-IR)spectroscopy and by ¹H NMR in such a way as to verify the presence ofthe azide group on each of the deprotonated terephthalate ligands. Thus,the spectrum that is obtained by FT-IR has a characteristic band of theazide group at 2,123 cm⁻¹. The ¹H-NMR analysis is implemented on asample of said IHM-2-N₃ hybrid solid according to the invention, afterdigestion and total dissolution of said sample in a DCl/D₂O/DMSO-d₆deuterated mixture according to an operating mode described in theliterature (Z. Q. Wang, S. M. Cohen, Journal of the American ChemicalSociety, 2007, 129, 12368-12369). Coupled to the FT-IR analysis, the¹H-NMR analysis confirms the presence of the N₃ azide group on thearomatic cycle of the deprotonated terephthalic ligand: δ=7.73-7.83 ppm,m, 3H, ArH. The 3 protons leading to the detection of the multipletcorrespond to the 3 protons carried by the aromatic cycle of the2-azido-terephthalate (N₃-bdc) ligand.

This invention also has as its object a process for the preparation ofthe IHM-2-N₃ crystallized hybrid solid. Said IHM-2-N₃ solid is preparedfrom the IHM-2 crystallized hybrid solid: said IHM-2 solid is acrystallized hybrid material with an organic-inorganic matrix thatcontains an inorganic network of metal centers based on the elementindium and connected to one another by organic ligands that are formedby the entity 2-aminoterephthalate O₂C—C₆H₃—NH₂—CO₂—. It has an X-raydiffraction diagram that includes at least the lines recorded in Table2. This diagram is obtained according to a method that is identical tothe one that is described above in this description for the IHM-2-N₃solid.

TABLE 2 Mean Values for d_(hkl) and Relative Intensities Measured on anX- Ray Diffraction Diagram of the IHM-2 Crystallized Hybrid Solid. 2Theta (°) d_(hkl) (Å) I/I_(o) 4.70 18.80 mf 8.12 10.88 ff 9.37 9.43 FF12.41 7.13 ff 13.12 6.74 ff 14.10 6.28 ff 14.76 6.00 ff 16.29 5.44 f16.95 5.23 f 18.83 4.71 mf 20.54 4.32 ff 21.07 4.21 ff 23.61 3.76 ff24.68 3.60 ff 24.99 3.56 f 26.01 3.42 ff 26.44 3.37 f 27.71 3.22 ff28.42 3.14 ff 29.73 3.00 f 30.14 2.96 ff 31.23 2.86 ff 32.96 2.72 ff33.47 2.68 ff 34.29 2.61 ff 35.42 2.53 ff 37.99 2.37 ff 41.75 2.16 ff42.73 2.11 ff 43.98 2.06 ff 49.18 1.85 ff 51.55 1.77 ff 53.58 1.71 ff54.45 1.68 ff where FF = Very High; F = High; m = Medium; mf = MediumLow; f = Low; and ff = Very Low. The relative intensity I/I_(o) isprovided in relation to a relative intensity scale where a value of 100is assigned to the most intense line of the X-ray diffraction diagram:ff < 15; 15 ≦ f < 30; 30 ≦ mf < 50; 50 ≦ m < 65; 65 ≦ F < 85; and FF ≧85.

Said IHM-2 solid has a three-dimensional structure in which theone-dimensional inorganic chains with an —In—O(H)— pattern are linked toone another by the 2-aminoterephthalate ligands (—O₂C—C₆H₃—NH₂—CO₂—,denoted NH₂-BDC). Each indium atom is hexa-coordinated: each indium atomis surrounded by two oxygen atoms of the hydroxyl groups that arelocated in apical position and four oxygen atoms that are obtained fromfour 2-aminoterephthalate ligands that are located in equatorialposition. In addition, each organic ligand —O₂C—C₆H₃—NH₂—CO₂— (NH₂-BDC)is connected to two indium atoms (a pair of atoms that are close toindium). A method for preparation of said IHM-2 solid is described inExample 1 of this patent application. In a more general manner, aprocess for preparation of the IHM-2 solid comprises at least thefollowing stages:

-   -   a) The dissolution of at least one indium precursor, preferably        indium nitrate, in at least one polar organic solvent,        preferably dimethylformamide (DMF),    -   b) The addition of 2-aminoterephthalic acid (NH₂—H₂-BDC) in        solution in at least one polar organic solvent, preferably        dimethylformamide (DMF),    -   c) The addition of a base, preferably selected from among        1,4-diazabicyclo[2,2,2]octane (DABCO),        1,8-diazabicyclo[5,4,0]undec-7-ene (DBU), triethylamine,        pyridine, soda and ammonia, in solution in at least one polar        organic solvent, in the mixture that is obtained in stage b),    -   d) The precipitation of the 2-aminoterephthalic acid and said        indium precursor with said base at a temperature of between 0        and 100° C., preferably between 10 and 60° C., for a period of        between 1 and 8 hours,    -   e) The filtration, and the washing, and    -   f) The drying of the product that is obtained.

The reaction mixture that is obtained at the end of said stage c)advantageously has the following molar composition: 1 precursor ofindium: 1 2-aminoterephthalic acid: 2 bases: 40 to 500 polar solvent(s)S. The formulation of this molar composition is expressed in terms ofmolar equivalents.

The process for preparation of the IHM-2-N₃ solid of the invention makespossible the replacement of the —NH₂ amine group that is present in theIHM-2 solid by the N₃ azide group. The process for preparation accordingto the invention comprises at least the following stages:

i/ Introduction, into a polar solvent S, of at least said IHM-2crystallized hybrid solid, at least one organic compound Q that containsan N₃ azide group, and at least one intermediate reagent R that containsan NO₂ nitrite group in a proportion such that the reaction mixture hasthe following molar composition, based on a molar equivalent of the —NH₂group that is present in the IHM-2 solid:1IHM-2:1-100R:1-80Q:100-400S

ii/ Reaction of said reaction mixture at a temperature of between 0 and100° C. for a period of between 1 and 24 hours to obtain said IHM-2-N₃crystallized hybrid solid,

iii/ Filtration, and then washing of said IHM-2-N₃ crystallized hybridsolid,

iv/ Drying of said IHM-2-N₃ crystallized hybrid solid.

In accordance with said stage i) of said process for the preparation ofthe IHM-2-N₃ crystallized hybrid solid according to the invention, saidIHM-2 crystallized hybrid solid is dried in advance before beingintroduced into said polar solvent. The drying of said IHM-2crystallized hybrid solid is advantageously implemented at a temperatureof between 20 and 100° C. for a period of between 1 and 24 hours, veryadvantageously for a period of approximately 12 hours. The drying isdone in air or under vacuum, in a preferred manner under vacuum.

In accordance with said stage i) of the process for preparationaccording to the invention, said organic compound Q that contains an N₃azide group is advantageously selected from among trimethylsilyl azide(TMS-N₃, (CH₃)₃SiN₃), triflyl azide (TfN₃, where Tf=CF₃SO₂), p-tosylazide (TsN₃ or 4-methylbenzenesulfonyl azide of formula C₆H₄(CH₃)SO₂N₃),and sodium azide (NaN₃). In a preferred manner, said organic compound Qthat contains an N₃ group is trimethylsilyl azide (TMS-N₃).

In accordance with said stage i) of the process for preparationaccording to the invention, said intermediate reagent R that contains anNO₂ nitrite group is advantageously selected from among alkalinereagents such as sodium nitrite (NaNO₂) and calcium nitrite (Ca(NO₂)₂),metal reagents, and alkoyl-type reagents such as tert-butyl-nitrite(tBuONO, (CH₃)₃CONO). In a very preferred manner, said intermediatereagent R that contains an NO₂ nitrite group is tert-butyl-nitrite(tBuONO). Said intermediate reagent R that contains an NO₂ nitrite groupensures the formation of a diazonium salt that next reacts with theorganic compound Q.

The polar solvent S that is used in said stage i) of the process forpreparation according to the invention is preferably volatile. It isvery advantageously selected from among tetrahydrofuran (THF) andacetonitrile.

In accordance with said stage i) of the process for preparationaccording to the invention, the reaction mixture preferably has thefollowing molar composition, based on a molar equivalent of the —NH₂group that is present in the IHM-2 solid:1IHM-2:25-50R:20-60Q:100-200S

Said reaction stage in accordance with said stage ii) of the process forpreparation according to the invention is preferably implemented at atemperature of between 0 and 60° C., and even more preferably at ambienttemperature. The reaction mixture is stirred using a magnetic stirrer.The reaction period is between 1 and 24 hours, preferably between 5 and15 hours, and most often approximately 12 hours. The solid that isobtained at the end of said stage ii) is an IHM-2-N₃ crystallized hybridsolid that has an X-ray diffraction diagram that includes at least thelines that are recorded in Table 1.

In accordance with said stage iii) of the process for preparationaccording to the invention, said IHM-2-N₃ crystallized hybrid solid thatis obtained at the end of said stage ii) is filtered and then washedwith suitable solvents. The washing of said IHM-2-N₃ solid is preferablyimplemented by a first washing sequence by means of polar solvents, forexample THF, followed by a second washing sequence by means of volatilesolvents, for example dichloromethane. The washing stage of saidIHM-2-N₃ crystallized hybrid solid is initiated, for example, byimplementing 3 sequences of washing with THF followed by 3 sequences ofwashing with CH₂ Cl₂ dichloromethane.

In accordance with said stage iv) of the process for preparationaccording to the invention, said IHM-2-N₃ crystallized hybrid solid isdried. The drying is done in air or under vacuum at between 20° C. and100° C., preferably at ambient temperature, for a period that variesbetween 1 and 24 hours. In a preferred manner, the drying is done atambient temperature under vacuum for a period that varies between 1 and24 hours, most often approximately 12 hours.

The solid that is obtained at the end of stage iv) is identified asbeing the IHM-2-N₃ crystallized hybrid solid according to the invention.The analyses that are implemented on the solid that is obtained at theend of the process for preparation according to the inventiondemonstrate the effectiveness of the treatment by post-modification. Inparticular, the analysis that is implemented on the IHM-2-N₃crystallized hybrid solid by XRD demonstrates that the treatment offunctionalization by post-modification that makes it possible to replacethe —NH₂ amino group by the —N₃ azide group does not affect thestructure and the crystallinity of the solid. The FT-IR analysis revealsthe presence of the —N₃ azide group on each of the terephthalate ligandsin the IHM-2-N₃ solid. Coupled to the FT-IR analysis, the ¹H-NMRanalysis confirms the presence of the —N₃ azide group on each of theterephthalate ligands in the IHM-2-N₃ solid and makes it possible toestimate the rate of modification of the amino groups into N₃ azidegroups. In accordance with the process for preparation according to theinvention, this rate of modification is very high, i.e., at least equalto 95%, and preferably at least equal to 98%. The rate of modificationis calculated by quantifying the decrease in the relative area of thesignals of aromatic protons of the IHM-2 form relative to those of theIHM-2-N₃ form. The ¹H-NMR spectrum of the IHM-2-N₃ solid according tothe invention has new signals that are linked to the appearance of anintegral multiplet for 3 protons, which correspond to the 3 protons thatare carried by the aromatic cycle of the 2-azido-terephthalate (N₃-bdc)ligand.

EXAMPLES

The IHM-2 and IHM-2-N₃ crystallized hybrid solids that are obtained atthe end of the implementation of the preparation protocols illustratedby the following Examples 1 and 2 have been analyzed by X-raydiffraction, by Fourier Transform Infrared (FT-IR) spectroscopy, and bynuclear magnetic resonance of hydrogen (¹H NMR).

The X-ray diffraction diagrams are obtained by radiocrystallographicanalysis by using the conventional powder method by means of a BrukerD5005 diffractometer (CuKα₁₊₂=0.15418 nm) that is equipped with agraphite curved rear monochromator and a scintillation detector. Theanalyses of the solids have been recorded with the Debye-Scherrer methodfrom 3 to 80° (2θ) with a pitch of 0.02° for 8 seconds.

The infrared analyses are done using KBr pellets on a Bruker Vector 22FT-IR device with a useful operating range of: 4,000-400 cm⁻¹.

The nuclear magnetic resonance spectra in solution are obtained using aBruker Avance 250 NMR spectrometer (5.87 T, 250 MHz for 1H).

Example 1 Preparation of the IHM-2 Crystallized Hybrid Solid

4.82 ml (3.3 mmol) of an indium nitrate solution (Alfa Aesar, 99.99%) indimethylformamide (DMF, Aldrich, 99.8%) at a concentration of 0.68 mol/lis placed in a Pyrex receptacle with an inside volume of 100 ml, and10.06 ml (3.3 mmol) of a 2-amino-1,4-benzene dicarboxylic acid solution(Alfa Aesar, 99%) in DMF at a concentration of 0.33 mol/l is added. Themixture is stirred for 5 minutes using a magnetic stirring mechanism.After homogenization, 4.83 ml (6.7 mmol) of a solution of1,4-diazabicyclo[2,2,2]octane (DABCO, Aldrich, 98%) in DMF at aconcentration of 1.38 mol/L is added. The solution is stirred for 120minutes at ambient temperature. After cooling and filtration, thecrystallized solid that is obtained is washed (24 hours) with a hotsolution (160° C.) of DMF and then is impregnated with dichloromethane(48 hours). After drying in air at a temperature that is equal to 120°C. for a period of 12 hours, a material in powder form that consists ofIHM-2 crystals is obtained.

Said IHM-2 crystallized hybrid solid is analyzed by X-ray diffraction,by Fourier Transform Infrared spectroscopy, and by nuclear magneticresonance of hydrogen (¹H NMR).

The X-ray diffraction analysis reveals that said solid that is obtainedin Example 1 is identified as consisting of IHM-2 solid: it exhibits anX-ray diffraction diagram that includes at least the lines that arerecorded in Table 2.

The FT-IR analysis reveals the presence of the —NH₂ amino group in theIHM-2 IR (KBr pellet) solid, υ (cm⁻¹): 3450, 3379, 2975, 1660, 1623,1556, 1423, 1381, 1256, 1044, 829, 790, 770, 699, 579, and 522. Thebands at 3,450 and 3,379 cm⁻¹ are attributed to the amine group.

The ¹H-NMR analysis is implemented on a sample of the IHM-2 solid, afterdigestion and total dissolution of the sample in a DCl/D₂O/DMSO-d₆deuterated mixture according to the operating mode that is described inthe literature (Z. Q. Wang, S. M. Cohen, Journal of the AmericanSociety, 2007, 129, 12368-12369): 10 mg of IHM-2 hybrid solid isdigested and dissolved in 1.5 ml of deuterated DMSO and 0.2 ml of adilute DCl solution (prepared from a solution that contains 0.23 ml ofDCl/D₂O at 35% and 1 ml of deuterated DMSO).

The ¹H-NMR analysis also reveals the presence of the —NH₂ amino group inthe IHM-2 solid. ¹H NMR, 250 MHz, t.a, δ (ppm/(DCl/D₂O/DMSO-d₆)): 7.15(d, 1H, J=8.3 Hz); 7.44 (s, 1H); 7.80 (d, 1H, J=8.3 Hz).

Example 2 Preparation of the IHM-2-N₃ Solid by Post-Modification of theIHM-2 Hybrid Solid

80 mg (0.26 mmol equivalent of —NH₂) of IHM-2 solid, obtained at the endof the process that is illustrated in Example 1, is vacuum-dried at 85°C. and then placed in a pill machine (8 ml capacity) with 3 ml (37 mmol,142 molar equivalent) of THF, 1.48 ml (12.48 mmol, 48 molar equivalent)of tBuONO (Aldrich), and 1.3 ml (9.88 mmol, 38 molar equivalent) ofTMS-N₃ (Aldrich). After 12 hours of reaction at ambient temperature, thesolid is filtered and then washed three times with 8 ml of THF (CarloErba), and then three times with 8 ml of CH₂ Cl₂ before beingvacuum-dried at ambient temperature for one night.

The solid that is obtained has been analyzed by X-ray diffraction andidentified as consisting of IHM-2-N₃ crystallized hybrid solid: thediffractogram that is implemented on the IHM-2-N₃ solid is the one thatis provided by FIG. 1. The analysis that is implemented on the IHM-2-N₃crystallized hybrid solid by XRD demonstrates that the post-modificationtreatment that makes it possible to replace the —NH₂ amino group by the—N₃ azide group does not affect the structure and the crystallinity ofthe solid.

The FT-IR analysis reveals the presence of the —N₃ azide group on eachof the terephthalate ligands in the IHM-2-N₃ solid. The spectrum that isobtained by FT-IR has a characteristic band of the azide group at 2,123cm⁻¹. The bands at 3,450 and 3,379 cm⁻¹ that correspond to the —NH₂group have disappeared.

The ¹H-NMR analysis is implemented on a sample of the IHM-2-N₃ hybridsolid, after digestion and total dissolution of the sample in aDCl/D₂O/DMSO-d₆ deuterated mixture according to an operating mode thatis described in the literature (Z. Q. Wang, S. M. Cohen, Journal of theAmerican Chemical Society, 2007, 129, 12368-12369): 10 mg of IHM-2-N₃hybrid solid is digested and dissolved in 1.5 ml of deuterated DMSO and0.2 ml of a dilute DCl solution (prepared from a solution that contains0.23 ml of DCl/D₂O at 35% and 1 ml of deuterated DMSO).

The ¹H-NMR analysis confirms the presence of the N₃ azide group in thearomatic cycle of the deprotonated terephthalic ligand. ¹H NMR, 250 MHz,t.a, δ (ppm/(DCl/D₂O/DMSO-d₆)): δ=7.73-7.83 ppm, m, 3H, ArH. The 3protons that lead to the detection of the multiplet correspond to 3protons that are carried by the aromatic cycle of the2-azido-terephthalate (N₃-bdc) ligand.

The comparison of the IR and ¹H-NMR spectra that are obtained for theIHM-2 solid and for the IHM-2-N₃ solid demonstrates the effectiveness ofsaid post-modification treatment—with the comparison of ¹H-NMR spectraobtained for the IHM-2 solid and for the IHM-2-N₃ solid making itpossible to estimate at 98% the rate of modification of the amino groupsinto N₃ azide groups—by quantifying the decrease of the relative area ofthe signals of the IHM-2 solid relative to those of the IHM-2-N₃ solid.

The invention claimed is:
 1. A IHM-2-N₃ crystallized hybrid solid withan organic-inorganic matrix, of a three-dimensional structure,containing an inorganic network of indium-based metal centers that areconnected to one another by organic ligands that consist of the entity—O₂C—C₆H₃—N₃—CO₂— (N₃-bdc ligand), whereby said solid exhibits an X-raydiffraction diagram that includes at least the lines that are recordedin the table below: 2 Theta (°) d_(hkl) (Å) I/I_(o) 4.68 18.87 mf 8.1210.88 ff 8.95 9.87 ff 9.37 9.43 FF 11.78 7.51 ff 11.94 7.41 f 12.43 7.11ff 14.08 6.28 ff 14.74 6.00 ff 16.34 5.42 f 16.95 5.23 ff 17.45 5.08 ff18.01 4.92 ff 18.80 4.72 mf 18.96 4.68 f 21.03 4.22 ff 23.53 3.78 ff23.82 3.73 ff 25.04 3.55 ff 26.45 3.37 ff 26.68 3.34 ff 27.41 3.25 ff28.33 3.15 ff 28.61 3.12 ff 29.74 3.00 ff 31.24 2.86 ff 32.35 2.77 ff34.20 2.62 ff 35.47 2.53 ff 38.06 2.36 ff 41.71 2.16 ff 42.02 2.15 ff42.74 2.11 ff 43.04 2.10 ff 45.92 1.97 ff 54.57 1.68 ff where FF = VeryHigh; F = High; m = Medium; mf = Medium Low; f = Low; and ff = Very Low,with the relative intensity I/I_(o) being provided in relation to arelative intensity scale where a value of 100 is assigned to the mostintense line of the X-ray diffraction diagram: ff < 15; 15 ≦ f < 30; 30≦ mf < 50; 50 ≦ m < 65; 65 ≦ F < 85; and FF ≧ 85,

and whereby H—N MR analysis confirms the presence of an N₃ azid group onan aromatic cycle of a deprotonated terephthalic ligand: 8=7.73-7.83ppm, m, 3H, ArH, 3 protons leading to the detection of the multipletcorresponding to 3 protons carried by the aromatic cycle of the (N₃-bdc)ligand.
 2. The IHM-2-N₃ crystallized hybrid solid according to claim 1,such that it exhibits a crystalline structure that is identical to theone of the IHM-2 crystallized hybrid solid that has a chemicalcomposition that has In(OH)(—O₂C—C₆H₃—N₃—CO₂—) for its base pattern. 3.The IHM-2-N₃ crystallized hybrid solid according to claim 1, such thateach —O₂C—C₆H₃—N₃—CO₂— organic ligand is connected to two indium atoms.4. The IHM-2-N₃ crystallized hybrid solid according to claim 1, suchthat each indium atom is surrounded by two oxygen atoms of hydroxylgroups that are located in apical position and four oxygen atoms thatare obtained from 4 N₃-bdc ligands that are located in equatorialposition.
 5. The IHM-2-N₃ crystallized hybrid solid according to claim1, such that it exhibits a chemical composition that hasIn(OH)(—O₂C—C₆H₃—N₃—CO₂—) for a base pattern.
 6. A process for thepreparation of an IHM-2-N₃ crystallized hybrid solid according to claim1, starting from an IHM-2 crystallized hybrid solid which processcomprises at least the following stages: i/ Introduction, into a polarsolvent S, of at least said IHM-2 crystallized hybrid solid, at leastone organic compound Q that contains an N₃ azide group, and at least oneintermediate reagent R that contains an NO₂ nitrite group in aproportion such that the reaction mixture has the following molarcomposition, based on a molar equivalent of the —NH₂ group that ispresent in the IHM-2 solid:1IHM-2:1-100R:1-80Q:100-400S ii/ Reaction of said reaction mixture at atemperature of between 0 and 100° C. for a period of between 1 and 24hours to obtain said IHM-2-N₃ crystallized hybrid solid, iii/Filtration, and then washing of said IHM-2-N₃ crystallized hybrid solid,iv/ Drying of said IHM-2-N₃ crystallized hybrid solid.
 7. The processfor preparation according to claim 6, such that said IHM-2 crystallizedhybrid solid is dried in advance before being introduced into said polarsolvent.
 8. The process for preparation according to claim 6 such thatsaid organic compound Q that contains an N₃ azide group is selected fromamong trimethylsilyl azide (TMS-N₃), triflyl azide (TfN₃), p-tosyl azide(TsN₃), and sodium azide (NaN₃).
 9. The process for preparationaccording to claim 6, such that said intermediate reagent R thatcontains an NO₂ nitrite group is tert-butyl-nitrite (tBuONO).
 10. Theprocess for preparation according claim 6, such that said polar solventS is selected from among tetrahydrofuran (THF) and acetonitrile.
 11. Theprocess for preparation according to claim 6, such that said reactionmixture has the following molar composition:1IHM-2:25-50R:20-60Q:100-200S.
 12. The process for preparation accordingto claim 6, such that said stage ii) is implemented at ambienttemperature.
 13. The process for preparation according to claim 6, suchthat the period of said stage ii) is between 5 and 15 hours.